Gonorrhea, one of the most common sexually transmitted diseases in the United States, is increasingly showing resistance to one of the last known effective antibiotic treatments, leading researchers from the Centers for Disease Control to "sound the alarm" about potentially untreatable forms of the disease.
That's serious stuff. Untreated gonorrhea is extremely unpleasant, and can have awful long-term side effects like infertility, ectopic pregnancy, and bladder cancer (in men).